Ladder



FIG. 1 is a perspective view from above, to the front and the right side of the new design for a ladder;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a left side elevation view thereof.

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

In the drawings, the broken lines are for the purpose of illustrating portions of the article that form no part of the claimed design. 

CLAIM The ornamental design for a ladder, as shown and described. 